1. Field of the Invention
The invention is in the field of devices for producing closures by injection molding, in particular devices for producing and closing hinged closures.
2. Discussion of Related Art
The prior art discloses capping devices for capping hinged closures within an injection mold. Apart from embodiments which only enter from the side after the injection mold has been opened, there are known capping devices which are integrated in the injection mold. These integrated capping devices are recessed into the mold halves and remain in the injection mold when it is closed.
U.S. Pat. No. 4,340,352 from the company Global Precision Inc. was published in 1982 and relates to a capping device which enters from the side. A cap connected to a lower lid part by means of a hinge is raised by means of a pin. Subsequently, a closing arm mounted on a slide enters from the side. Controlled by means of a slotted plate, this closing arm lifts the cap and closes it.
WO0228622A from the company Schoettli AG was published in 2002 and concerns a device which comes into action after the opening of an injection mold with a number of cavities. The lower closure parts are initially only lifted a little out of their cavities while seated on a core. The upper closure parts (lids), connected to the lower closure part by means of a hinge, are thereby completely ejected and freed. For the closing of the lids, a frame is made to enter between the mold parts after the opening of the mold. Arranged on the frame are arms with closing rollers, by means of which the closures can be closed. The device has a comparatively complicated structure.
U.S. Pat. No. 5,744,082A from the company Marland Mold Inc. was published in 1998 and concerns a capping device integrated in an injection mold. A movable part of the cavity is mounted such that it can turn about an axis and, after the mold has been opened, can be rotated by 180° for closing the cap. The device has various disadvantages. On the one hand, it requires complicated mold parting. On the other hand, the closure cannot get out of the way during the closing. For this reason, this device can only be used for closures of certain geometries.
EP1386712 from the company BVA SRL. was published in 2004 and concerns a capping mechanism integrated in an injection mold, integrated by means of camways. The capping mechanism is recessed in an integrated manner in one of the mold planes, on the core side, during the injection molding. After the opening of the mold, a closing rod is intended to be moved under the cap along a slotted link, lift the cap and then close it. It is not clear by what mechanism and how the rod is supposed to be moved.
WO03049917 from Jes Gram describes a device for producing hinged closures from a number of material components. By means of an injection mold with a turning central part, hinged closures are produced in two parting planes. The basic idea is to close these hinged closures before, or at the latest during, the ejection from the device. The document does not disclose anything as to how this can actually be accomplished.
US2009084071A from Moulindustrie SAS shows a capping device which is arranged inside an injection-molding device. It has a number of closing rods, which are driven by means of racks and act on the closures when the injection-molding device is open.
The prior art discloses devices which sort closures ejected from an injection mold, in order then to feed them individually to a capping device. These devices are large and comparatively expensive. The closures are moved along complicated slotted links by vibration and aligned. A disadvantage of this principle is that closures with surfaces of high quality are often scratched. A further disadvantage is that the sorting installations tend to become jammed, which requires intensive, costly care.